They are actually used for finding Alien Codes - you can find 3 in each level you play as Clank - and each code has a specific description to go with them. The first one is right after you get the Sunglasses, euip them and look at the wall behind the first guard inside the bulding in front of you, then zoom in on the glowing code, and press X when it says so to unscramble the code Get all the codes in the game to unlock the HIG Treehouse

I don't know how to find the cards, you just come across them as Qwark and Clank, but i do know that getting all 3 will unlock a special door in the HIG Treehouse that leads to a special secret!